Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2004
Publication Date: 12/16/2004
Citation: Davis Jr, K.B. 2004. Temperature affects physiological stress responses to acute confinement in sunshine bass (Morone chrysops x Morone saxatilis). Comparative Biochemistry and Physiology. 139:433-440. Interpretive Summary: The temperature at which fish are handled and transported can drastically affect the success of these operations. Mortality and disease resistance can be affected during stressful conditions by increased plasma cortisol and glucose and decreased electrolyte concentrations. Sunshine bass were exposed to a standard low-water confinement stress at temperatures ranging from 5 to 300 C and plasma cortisol, glucose and chloride were measured before, during and after the stress. When fish were stressed at 200 or higher these physiological changes were higher and required a longer recovery time. Responses at 5 or 100 were low or absent. The quantitative responses at 150 C were moderate and recovery rapid; therefore a water temperature around 150 C is recommended when handling sunshine bass.
Technical Abstract: Sunshine bass (Morone chrysops X M. saxatilis) were subjected to a standard 15-min low-water confinement stress at temperatures ranging from 5 to 300 C. Stress was evaluated by measuring blood hematocrit, plasma chloride, glucose and cortisol. Fish acclimated to 300 C had initial glucose concentrations below those acclimated to 5 and 100 C. Fish survived the conditions imposed at every temperature except 30 C, where 15 out of 42 fish died during the stress and recovery protocol. The general pattern was an initial increase in hematocrit, followed by a delayed decrease in hematocrit and chloride, and an increase in plasma glucose and cortisol. In general, fish stressed at temperatures below 200 C had lower and more delayed changes in plasma glucose and cortisol than fish tested at 20, 25 and 300 C. Quantitative responses for glucose and cortisol were moderate and recovery rapid in fish stressed at 10 and 150 C; therefore, this range of water temperature is recommended when handling sunshine bass.